Method of attaching shoe heels



y 1 G. B. BRITTON METHOD OF ATTACITIING SHOE HEELS Filed March 2, 1936 2Sheets-Sheet l lhll/ENTOE: GLENN fi- Ben-r0, m ZQ Arroems-K July 6,1937. e. B. BRITTON METHOD OF ATTACHING SHOE HEELS Filed March 2', 19362 Sheets-Sheet 2 Patented July 6, 1937 'i OFFICE METHOD or ATTAOHINGSHOE; HEELS Glenn B. Britten, Hannibal,

Mo., assignor to In- Application March 2, 1936, Serial No. 66,518 11Claims. (o1. 12+147) The present invention relates to a method ofnailing heels to shoes, and in particular blind nailing rubber heels.This application is a companion case to Serial No. 66,519, filedconcurrently herewith.

In order to understand the invention, it may be observed that blindnailing is nailing to shoes heels having no holes or other guides orindications for the directing of the nails into their proper locations.It is understood that composition heels, such as rubber heels, haveaccurately located washers embedded therein, and that it is essentialthat the nails pass through these washers in order to obtain asatisfactory fixing of the heel to the shoe. The lack of visible guidesor indications as to the location of the washers presents problems thatare solved by the subject matter hereof.

In the ordinary open nailed heel, holes extend from the tread surface ofthe heel to these washers, so that the nails may enter these holes andbe driven until the head abuts the washer. These holes not only indicatethe location of the washers, but in automatic nailing machinery theyguide the nails so that the points will pass through the holes in thewashers. Furthermore, rims are provided that are upstanding from thetread surface of the heel around the holes and each of these rims has achamfered crater, so that in case the nail is brought up to the heelslightly out of alignment the crater or ohamfered inner surface of therim will direct the nail into proper alignment so that it will passthrough the hole in the washer.

In blind nailed heels, these rims and craters are not present. Prior tothe present invention, there was no efiective means of driving anddirecting the nail from the tread surface through the hole in thewasher. Ordinarily the nail was simply forced to penetrate the heeldirectly with only as tolerances of the nailing machine would give. Thisproved unsatisfactory, since, in a prohibitive number of instances inproduction, buckling, or shooting of the nails, occurred, withthe'result that the heel attachment would be defective, necessitatingthe replacement of the heel, or at least replacement of the defectivelydriven nails.

It is an object of the present invention to provide a method for blindnailing heels and in particular rubber heels that secures accuratedirecting of the nails, so that they properly enter the washers.

It is a further object of the invention to correct any initial or earlymisalignment of the nails much accuracy as the necessarily freeproducedby conditions in the die block or other means in which the nailsare held.

It is a further object of the invention to cor- V rect or prevent anymisalignment during the driving of the nails.

It is a further object of the invention to reduce the distance thro ghwhich the nail must travel inside the heel. Y

It is a further object of the invention to provide a method of drivingnails blindly in rubber heels in such wise that the cut through whichthe nail penetrates the tread surface of the heel will be automaticallyclosed so as to leave no Fig. 3 is a front elevation of the heel ringwith aguide plate in place;

Fig. 4 is a section on the line 44 of Fig. 2.

Fig. 5 is a bottom view of the device shown in Fig. 2 clearly'disclosingthe guide plate.

Fig. 6 is a View of the device in working'relation with the nailingmachine, in one stage of its operation.

Fig. 7 is a view similar to Fig. 6 in a subsequent 0 stage of operation.

Fig. 8 is a view similar to Figs. 6 and 7 in the third stage ofoperation.

Fig. 9 is an enlarged section of a portion of the heel ring and guideplate with the heel thereon in the stage shown in Fig. 6.

Fig. 10 is a view similar to Fig. 9 butin the stage shown in Fig. 7.

Fig. 11 is a section of completely attached heel.

Referring to Figs. 1 shown a heel ring 29. This ring is provided with aninternal cut-out portion 2| accurately formed to the shape of the heelbut sufiiciently larger than the outside dimensions thereof. to permitthe heel toenter the cut-out with a smooth, sliding lit. The depth ofthe walls defining the cut-out is only slightly less than the thicknessof the heel to be nailed. This heel ring is provided with ribs 22 on itsopposite sides for a purpose to be described. A bevel 23 is provided inthe forward end of the ring to accommodate the shank of a shoe on whicha heel is being attached.

to 5 inclusive, there is 40 Inset into the bottom of the heel ring 20 isa guide plate 24. This guide plate is very ac- Cfl curately fitted intothe heel ring and is secured thereto by means of suitable attachingscrews 25. This guide plate has upstanding from the inner surfacethereof. nipples 26 that are somewhat tapering on their outer surfaces.Holes 2? extend through these nipples. These holes terminate at theouter surface "of the .guide plate in chamfercd cuts 253. It will beseen that the holes 2i with the chamfers 28 provide a funnel effect toguide the nails.

A rubber heel 30 is shown. This heel is provided with cupped metalwashers 35, the tops of which normally are located about one-sixteenthof an inch, more or less, below the attaching surface of the heel. Inthe heel of the present invention, an extended hole 32 extends towardthe tread surface below the hole of the washer and terminates some shortdistance, such as one-sixteenth of an inch, inward from the treadsurface. It is preferable that the thickness of the rubber between thebottom of. the hole 32 and the tread surface be no greater than thediameter of the hole. As is usual, a hole 33, somewhat larger than thehole 32, extends from the washer 35 to the attaching surface.

As previously described, the cut-out 2! in the heel ring is accuratelyshaped to the dimension of the heel. With the guide plate 25 in positionon the heel ring, the holes 2'5 are accurately aligned with the holes inthe washers SI and also with the holes 32 in the heel. The heel ring islocated in the ring carriage 35 of the nailing machine, as shown inFigs. 6 to 8, inclusive, the flanges 22 engaging in suitable channels inthe carriage. The die block 36 of the nailing ma chine is then loadedwith nails 3? that rest in suitable holes 38 and which are adapted to beejected by drivers 39. The die block 3%: fits closely up against theguide plate 24 and the holes 38 therein align with the chamfered flaresof the holes 2? in the guide plate. The ring carriage is movablelaterally for replacement of the ring, and for reloading of the dieblock with nails.

At this time, it will be understood that the heel 38 is duly placed inthe heel ring 2%. A leather heel base it, somewhat larger than the heel,is placed over the heel and held in position by the base holder elementsM. The shoe being heeled is shown at 52 mounted on a last 43, which lastis supported on a member 45 that controls its ascent and descent. Theshoe includes an outsole 65 and an insole 16. A metal clinching plate llis located between the last and the insole.

The method of the present invention comprises thus locating the abovedescribed heel in position within the ring and on the guide plate 2%.This is the first step, as shown in Fig. 6. It will be understood thatthe driving head is loaded, as shown. In the second step, as shown inFig. 7, the last is lowered until it contacts with the heel base. Acertain amount of pressure is applied to "the last which compresses theheel until the heel base lb, previously noted as being somewhat largerthan the heel, strikes the heel ring 26. This compression is calledpreliminary pressure. The depth of the heel ring relative to the depthof the heel itself determines what portion of. this preliminary pressureis applied to the heel itself, since when the heel base comes intocontact with the heel ring, any additional pressure,

while available for steadying the last, is not transmitted to the heel,but is absorbed by the heel base and ring. Thus the pressure actuallyapplied to the heel itself is limited, and independent of the maximumlimits of the total preliminary pressure beyond that minimum re quiredto seat the heel base onto the ring.

However, another and perhaps more vital feature of this relatively deepheel ring and its operation is that the heel, when thus compressed,cannot deform laterally, being confined by the walls of the heel ring.Consequently, the entire force applied to the heel is employed inforcing the heel down over the nipples 26. Any lateral deformation wouldcause displacement of the washers, destroying their alignment with theholes 2'! and the nails.

In this preliminary pressure stage, as is shown in Fig. 10, the nipplepenetrates the tread surface of the heel with a wedging action, althoughpreferably it does not cut this surface. As the apex of the nipple andthe hole 21 are in alignment with the hole 32 in the heel, thepenetration of the nipple will tend to bring the hole 2! near to thehole 22, thereby reducing the unguided travel of. the nail point. Whileit is not precisely understood what internal distortion takes place, itis believed that the following occurs: The rubber, in being forced overeach nipple 26, tends to stretch or flow downwardly and outwardly alongthe surface of the nipple, this being the normal action to be expectedfrom such a conical wedge. As the thickness of rubber between the top ofeach nipple and the hole 32 is small, the tendency is for this thin wallof rubber to be distended across the top of the opening 21 in the nipple2S, producing something of a membranous effect. Furthermore, it isbelieved that the bottom portion of the hole 32 in this action iswidened and stretched across the opening 21 so that the walls of theholes 32 above the nipple downwardly diverge from the axis of the hole.This causes the hole 32 to approximate, at least, the size of the hole21 in the guide plate. It furthermore seems likely that the portion ofthe hole 32 above this distended portion and near to the washer 3| isreduced in dimension so that possibly it may be nearly closed. Thiscauses the hole to be funnel-shaped, to guide the nail as will bedisclosed. This condition is shown in Fig. 10 and is the status of theheel and the nailing apparatus in the stage shown in Fig. 7.

In the next stage of operation, as shown in Fig. '7, the driver block israised so that the driving pins 39 eject the nails 31 and force themupwardly. The holes 38 in the die block are necessarily larger than thenails, since they must accommodate the heads of the nails withsufficient freedom to permit unrestricted action of the machine. As aconsequence, the nails may be ejected out of proper alignment with thewashers in the heel. However, with the present method, the chamferedportions 28 of the holes 21 will receive these misdirected nail pointsand redirect them into the holes 21. The nails will then pass throughthe holes 21 and the nipples 26 and into the distended and thinnedmembranous portion of the heel between the tops of the nipples 26 andthe hole 32. The nails then pass into the hole 32. Should they besomewhat deflected when they reach the holes 32, they will be realignedbecause of the converging of the walls of these holes, it being lessresistant for the nails to be thus redirected than to penetrate thewalls of the holes 32. The nails then will pass up through the top partof the holes 32 and through the washers in proper alignment. Theypenetrate the leather heel base 45, the outer sole 45, the inner sole 56and, upon striln'ng the clinching plate 47, are bent over, as shown inFig. 8, and secured in position.

The driving pins 39 are ing to the fact that the portion of the rubberheel penetrated by the nails and driving pins was under a spreadingtension, as soon as the pins are withdrawn and the heel removed from thenipples 25 on the guide plate, this tension will be relieved. Thisrelieving of the tension causes the holes produced by the nails and thedriving pins automatically to close up and leave only an althenwithdrawn. Ow-

most invisible cut in the tread surface of the heel.

The above method. is the preferred one. However, very satisfactoryresults may be obtained by the guide plate without the upstandingnipples, the chamfered openings 28, and the narrower holes 2'! servingto redirect and guide the nails. The preliminary pressure, of course,cooperates to secure a tight bond of heel to shoe, as it does in thepreferred process.

It will be seen that this method provides accurate blind nailing ofheels, and in addition attains the advantage of substantially closingthe nail hole after the operation is completed.

The invention having been described, what is claimed is:

1. In the method of nailing heels having washers therein to shoes, thesteps of providing a hole in the heel extending downwardly from thewasher hole to adjacent the tread surface of the heel, forcing the heelover a guide element having a hole therein which guide element projectsinto the heel with a wedging action toward said heel hole, and therebystretching the heel material below said heel hole so that it is undertension, forcing the nail through said guide element hole to be directedthereby, said heel material at said zone of tension, and into the holein the heel, and ultimately removing said guide element to permit reliefof the tension.

2. In the method of nailing to shoes heels having washers therein spacedfrom the tread sur face thereof, the steps of forcing the heel over aprojecting guide element to reduce the distance between the treadsurface and the washer hole, and passing a nail through said guideelement, and by its guidance through the hole in the washer.

3. In the method of nailing to shoes heels having washers therein spacedfrom the tread surface therecf, the steps of deforming the heel materialto reduce the distance between the tread surface and the washer, drivingthe hail from the tread surface through the deformation zone and throughthe washer, and ultimately relieving thedeformation to permit the heelto return to normal shape.

4. In the me hod of nailing to shoes elastic heels having washerstherein spaced from the tread surface thereof, the steps of deformingthe heel material to reduce the distance between the tread surface andthe washer, and also to place the heel material under spreading tensionin said portion between the washer and the tread surface, then driving anail through said deformed portion, said washer and into the shoe, andfinally relieving said deformation.

5. In the method of nailing to shoes elastic heels having washers spacedfrom the tread surface thereof, and having holes projecting toward thetread surface from the holes in the washers, but terminating short ofthe tread surface, the

3 steps of deforming said heel by a wedging action applied to the treadsurface in substantial alignment with the holes in the heel, and therebyreducing the distance between the tread surface and the heel hole, and.also deforming the hole so that the walls thereof diverge toward saidtread surface and converge toward the washer hole, then driving a nailthrough the tread surface at the point of deformation, to said'hole,guiding the nail by the converging walls of the hole through the washerhole and into the shoe, an finally relieving said deformation.

6. In the method of nailing to shoes elastic heels having washerstherein spaced from the tread surface thereof, the steps of locating theheel with the tread surface over a guide element through which the-nailsmay be projected, forcing the shoe down against the attaching surface ofthe heel to press the heel onto said guide element, and by said pressuredeforming the heel to reduce the distance between the washer and thetread surface of the heel, and driving nails through said guide element,said reduced portion of the heel, and into the shoe.

7. In the method of nailing to shoes elastic heels having washerstherein spaced from the tread surface thereof, the steps of locating theheel with the tread surface over a guide element through which thenailsmay be projected, placing a heel base over the attaching surface of theheel, forcing a shoe down against the heel base, and pressing the shoethereagainst to deform the heel, and thereby deforming the heel toreduce the distance between the tread surfaces and the washers, andplacingthe portion of the heel between the tread surface and washersunder tension radiating from an axial line drawn through the holes inthe washer, driving nails through the tread surface, the deformedportion, the washer and into the shoe, and ultimately relieving thedeformation to permit the heel to resume normal position and at leastsubstantially close the opening produced by the passage of the nail.

8. In a method of nailing heels to shoes, which heels are provided withwashers therein spaced from the tread surface thereof, the steps ofholding the heel with the tread surface over-nails, compressing the heelbut limiting the straining thereof to prevent lateral deformation,driving the nails toward said tread surface, and redirectand guidingsaid nails immediately adjacent said tread surface so that they arealigned with washers.

9. In a method of nailing rubber heels having washers therein to shoes,the steps of confining the heel to be nailed to prevent such lateral deaformation thereof as to displace the washers in said heel, applyingpressure against the upper surface of said heel to compress the samewhile thus confined, determining the amount of said pressure, directingnails toward the bottom surface of said heel, and guiding them into saidheel and toward the washers.

10. In a method of nailing to a shoe a heel provided with washers spacedfrom a substantially flat tread surface, the steps of inserting saidheel into a heel locator to position said substantially flat treadagainst projecting holed nail guide elements on a guide plate, pressingsaid heel against said elements to press the main area of the treadagainst the plate and the elements into the heel to place those portionsof the heel thereabout under tension, driving nails through saidelements and through said tensioned portions and securing means throughsaid elements and through said stretched portions and through and intoengaging relation with said washers, and releasing the pressure on saidheel to withdraw the same from engagement with the elements and theguide plate to relieve the tension set up by the stretching action tosubstantially close the holes made in the heel tread by the passage ofthe securing means.

GLENN B. BRITTON.

